Bunker (noun)

1. A reinforced underground shelter, especially one for protecting people during air raids.
2. A large storage container for coal, grain, or other materials.
3. A sand trap on a golf course.
4. A type of defense fortification used in military conflict.

Origin:

The word "bunker" originated in the late 17th century as a term used in golf, where it referred to a small, earthen shelter or pit where the ball was placed. the word later came to be used to refer to a type of underground shelter, especially during wartime.

Examples:

1. During the air raid, people rushed to the nearest bunker for safety.
2. The coal bunker was full and ready to be shipped to the power plant.
3. The golfer hit his ball into the bunker and struggled to get it out.
4. The bunker was heavily fortified and designed to withstand enemy attacks.
5. The storage bunker was used to keep grain and other food supplies safe.